Comanche Peak 2 - Status & History

Comprehensive reactor performance metrics, cycle analysis, and historical outage data.

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Composite Operational Excellence Score (0-100) — average percentile rank across 7 dimensions in three sub-scores: Reliability (capacity factor, forced outage days, B2B avg streak), Efficiency (fuel utilization, refuel duration), and Discipline (startup duration, scram count). 5-year window. Higher = more operationally excellent. Click to see the full breakdown.
48
Excellence
#51 of 94
Mid Quartile
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Days of continuous operation since the last outage ended. Has forced outage(s) since last refueling.
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Current Run
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Longest recorded period of continuous operation between outages (2008-04-18 to 2009-10-08).
538
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (463 days for this 18-month cycle unit) with no trips to 0% power.
8
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
92.2%
Capacity Factor
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Total number of scheduled refueling outages detected in the historical data.
19
Outages
since 1999
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Average time from first power generation (>0%) to sustained full power (≥95% for 2+ days) across the last 3 scheduled outages. Click to compare against the fleet on the Operator Efficiency Leaderboard.
3
Avg Startup
days (last 3)
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Average fuel utilization — percent of the designed fuel cycle that this unit consumes before refueling, derived from the historical burn-down trajectory. Higher = more efficient operator (refuels with less margin remaining; closer to coastdown). Computed as 100% minus the unit's average refuel-point fuel %, using the last 3 years where available, otherwise lifetime average. Click to compare against the fleet on the Operator Efficiency Leaderboard.
97.9%
Fuel Utilization
3yr avg
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NukeWorker's Operational Excellence Score is a composite 0–100 ranking of every active US nuclear unit across 7 publicly observable performance metrics, grouped into three sub-scores:
Reliability — capacity factor, forced outage days, B2B avg streak
Efficiency — fuel utilization, refuel duration
Discipline — startup duration, scram count
Each unit's metric is converted to a percentile across the active fleet. Sub-score = average of its components; composite = average of the three sub-scores. Use the time-window toggle below to switch between 3yr / 5yr / lifetime.
Time window — change how far back we look
NukeWorker's
Operational
Excellence Score
48/100
Mid Quartile · #51/94
5-year window

Comanche Peak 2 ranks #51 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Fuel Utilization (66th percentile). Weakest: Scrams (5-year) (16th percentile).

Reliability
54
Capacity factor + Forced outages + B2B streaks
Efficiency
59
Fuel utilization + Refuel duration
Discipline
31
Startup duration + Scram count
Cohort Rankings apples-to-apples comparison within each peer group
Reactor type: #35 of 61 PWR
Containment: #31 of 48 Dry Ambient (PWR)
Cycle length: #28 of 54 18-month cycle
Fleet rank above (51 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor 63th
92.5% (higher better, Reliability)
Forced Outage Days/yr 42th
4.8d (lower better, Reliability)
B2B Avg Streak 55th
522d (higher better, Reliability)
Fuel Utilization 66th
98.3% (higher better, Efficiency)
Refuel Duration 53th
32d (lower better, Efficiency)
Startup Duration 46th
4.7d (lower better, Discipline)
Scrams (5-year) 16th
0.8/yr (lower better, Discipline)

Each dimension's percentile is computed across the active US fleet (94 units with sufficient history). Sub-score = average of its component percentiles. Composite = average of the three sub-scores. 5-year window. View full leaderboard →

Methodology

NukeWorker's Operational Excellence Score is a composite ranking that combines 7 publicly observable performance metrics into a single 0-100 number per US nuclear unit.

How it's computed: Each unit's raw value is converted to a percentile (0-100) within the 94 active US units that have at least 2 completed refueling cycles. The 7 percentiles are averaged into 3 sub-scores (Reliability, Efficiency, Discipline), and those are averaged into the final composite.

Active window — 5-year:

  • Reliability — Capacity factor (5yr), forced outage days/yr (5yr), B2B avg streak (lifetime)
  • Efficiency — in-cycle fuel utilization (3yr), median refuel duration (5yr)
  • Discipline — robust mean startup duration, scrams/yr (5yr, annualised)

Cohort rankings: alongside the fleet rank, each unit gets ranked within its reactor type (PWR/BWR), containment design (Ice Condenser, Mark I, etc.), and cycle length (12/18/24-month). Useful for apples-to-apples comparisons.

What's excluded: subjective community ratings, confidential INPO ratings, financial metrics. We only use publicly available NRC + cycle data.

Why three windows? 5yr (default) is the industry standard. 3yr captures recent operational changes and post-pandemic recovery. Lifetime gives newer units a fair comparison and reveals long-term consistency.

Edge cases: units with fewer than 2 cycles (e.g., Vogtle 4) show "Provisional". Decommissioned units excluded.

Refresh cadence: recomputed daily. Each window cached separately.

A data-derived proxy for operational performance; not affiliated with INPO. INPO ratings are confidential and qualitative — ours is public and quantitative.

5-yr trend: 2021: 21/100 (#82/93)2022: 26/100 (#79/92)2023: 37/100 (#65/92)2024: 36/100 (#72/93)2025: 41/100 (#63/94)2026: 41/100 (#62/94) Stable vs 2025
Compare Comanche Peak 2 head-to-head with up to 3 other units. Compare now
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Duration of each outage in days, shown chronologically. Green bars are scheduled refueling outages, red bars are forced/unscheduled. The orange dashed line marks the average duration. Extended outages (>180 days) and D&D periods are excluded.

Outage Duration Trend

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Days between consecutive scheduled refueling outage starts, showing operating cycle regularity. The purple dashed line marks the average cycle length. Most U.S. reactors operate on 18-month (547 day) or 24-month (730 day) cycles.

Cycle Length History

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Time in days from first power generation (>0%) to sustained full power (≥95% for 2+ consecutive days) after each scheduled refueling outage. The dashed line marks the average. Includes startup testing holds and power dips.

Startup Duration Trend

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Monthly capacity factor with outage events overlaid as red bands. Green bars show average power level per month. Toggle to Daily view for raw daily data.

Power History

Scheduled
2026-05-04 In Outage 10+ 229d 2026-04-18 +16d
Scram # 57929
2025-09-15 2025-09-17 3 300d - -
Scheduled
2024-10-21 2024-11-19 30 214d 2024-10-14 +7d
Scram # 57033
2024-03-18 2024-03-21 4 4d - -
Scram # 57024
2024-03-13 2024-03-14 2 292d - -
Scheduled
2023-04-24 2023-05-26 33 526d 2023-04-23 +1d
Scheduled
2021-10-04 2021-11-14 42 108d 2021-10-18 -14d
Scram # 55295
2021-06-08 2021-06-18 11 392d - -
Scheduled
2020-04-20 2020-05-12 23 109d 2020-04-19 +1d
Scram # 54460
2020-01-02 2020-01-02 1 349d - -
Unscheduled
2019-01-16 2019-01-18 3 2d - -
Scheduled
2018-12-09 2019-01-14 37 116d 2018-10-02 (Enhanced) +68d (Enhanced)
Scram # 53550
2018-08-14 2018-08-15 2 258d - -
Scram # 53091
2017-11-26 2017-11-29 4 83d - -
Scram # 52945
2017-09-02 2017-09-04 3 23d - -
Unscheduled
2017-06-06 2017-08-10 66 32d - -
Scheduled
2017-04-03 2017-05-05 33 509d 2017-04-01 +2d
Scheduled
2015-10-04 2015-11-11 39 526d 2015-09-15 +19d
Scheduled
2014-03-30 2014-04-26 28 147d 2014-03-29 +1d
Scram # 49497
2013-11-02 2013-11-03 2 366d - -
Scheduled
2012-10-07 2012-11-01 26 186d 2012-10-01 +6d
Unscheduled
2012-04-02 2012-04-04 3 316d - -
Scram # 46863
2011-05-20 2011-05-22 3 25d - -
Scheduled
2011-04-03 2011-04-25 23 518d 2011-04-02 +1d
Unscheduled Startup Hold
2009-10-31 2009-11-01 2 2d - -
Scheduled
2009-10-08 2009-10-29 22 538d 2009-10-03 +5d
Scheduled
2008-03-30 2008-04-18 20 13d 2008-03-29 +1d
Unscheduled
2008-03-17 2008-03-17 1 504d - -
Unscheduled Startup Hold
2006-10-30 2006-10-30 1 5d - -
Scheduled
2006-10-08 2006-10-25 18 529d 2006-10-07 +1d
Scheduled
2005-03-27 2005-04-27 32 458d 2005-03-26 +1d
Unscheduled
2003-12-23 2003-12-25 3 56d - -
Scheduled
2003-10-05 2003-10-28 24 72d 2003-10-05 0d
Unscheduled
2003-07-09 2003-07-25 17 42d - -
Unscheduled
2003-05-15 2003-05-28 14 342d - -
Unscheduled
2002-06-07 2002-06-07 1 35d - -
Scheduled
2002-03-31 2002-05-03 34 512d 2002-03-31 0d
Scheduled
2000-10-01 2000-11-04 35 529d 2000-10-01 0d
Scheduled
1999-03-20 1999-04-21 33 75d 1999-03-20 0d
Unscheduled
1999-01-04 1999-01-04 1 - - -
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